There are both physical and psychological reasons for treating and/or destroying undesirable tissue, for example, by destroying excess cells (e.g., fat cells, acne, tattoo ink, wrinkles, lesions, etc.), stimulating, destroying or otherwise modifying tissue, etc. The physical reasons may include prevention of heart disease, stroke, and diabetes, for example, by removal fatty cells. The psychological reasons may include improvement of self-image, which may accompany treatments that may reduce or modify excess tissue. Removing or otherwise modifying excess undesirable tissue has started playing an important role in medical and cosmetic procedures.
For example, adipose tissue, or “fat”, is primarily located in the hypodermis, but may be found in other areas. The hypodermis is a layer of subcutaneous tissue located beneath the dermis. The cells are large compared to other cells in the outer layers of the body. They are generally round in shape, but may also be polyhedral when pressed together to form a “layer of fat”. The nucleus of adipose cells is located near the cell membrane. Most of the volume of the cell is composed of a single droplet of liquid consisting of 90% triglycerides. There is little to no water inside a fat cell. Outside the fat cell is an area comprised of reticular fibers and a plexus of small capillaries. The capillaries transfer the triglycerides from the adipose cell to other cells when the body needs to generate energy.
One of the known methods of removing excess adipose or fat tissue is liposuction. This is an invasive procedure in which the fat is destroyed mechanically and then extracted using a suction device.
In the case of acne, the output duct of the sebaceous gland becomes blocked due to processes in the dermis and epidermis. The lipids that are secreted by the sebaceous gland begin to accumulate. Also located in the sebaceous glands are P.Acnes bacteria. These thrive on the accumulated lipids and their population begins to grow. This triggers a response from the immune system as it tries to control the population of P.Acnes, resulting in acne inflammation.
The P.Acne bacteria contain porphyrins. The two major porphyrins found in the P.Acne bacteria are coproporphyrin and uroporphyrin. Both are measured in urine analysis too determine liver and kidney problems. The peak absorption for coproporphyrin is 402 to 403 nm and for uroporphyrin the peak absorption is at 406 to 407 nm. Recent studies have indicated that a third porphyrin called protoporphrin is also present, which has a primary absorption point at 430 mm
Some current therapies use drugs to control the events in the dermis and epidermis that lead to the blocking of the sebaceous gland. Other therapies try to lower the immune systems response to the P.Acne bacteria. Still others try to destroy the P.Acne bacteria, for example, by applying blue light at approximately 400 nm to destroy the P.Acnes bacteria. Blue light is a relatively high frequency energy with a relative low penetration ability, therefore substantial amounts of blue light may need to be transmitted.
It would be highly advantageous to have a non-invasive method for destroying or modifying tissue, which is relatively easy, efficacious, and cost effective to apply.